1. Previously Tonido Server software shipped with the built-in Sync App.2. Starting in 2017, the new server doesn't ship with the built-in sync app.3. The new Sync apps (Tonido Sync2) will synchronize files only with the new Tonido Server (2017).4. The old sync apps are obsolete and are no longer available because they had many bugs and it was not possible to support them properly.The new sync2 apps partially re-use the same technology from FileCloud Sync. (FileCloud Sync has faster realtime syncing in addition as well).